Motion Tracking works in viewport, but not in Render
It is impossible to help with motion tracking without looking at the shot, and the nodes used on the compositor.
A few comments:
An error of .8 pixels is still too high, you should aim for an error of .3 or lower.
Use the graph and dopesheet to see if any trakers have a high error value.
The most common error in tracking happens if you try to use the default solver on a shot where the camera is not moving, or where the camera is stationary and just tilting and panning. Those shots can only be solves as &quot;tripod&quot;. And will not give you any 3d information.
If you haven't already please read the detailed post on this site on motion tracking:
How can I get better results when doing camera motion tracking?